Bioavailability and stability enhancement of natural isoflavones of Saraca asoca by cryogenic encapsulation technique

Abstract

Background: The detailed study to overcome the limitations related to oral drug release and better encapsulation efficiency of the Saraca asoca extract has not been reported, despite having so many uses as sacred as well as a good medicinal plant. Objective: The aim of the present study was to fabricate a S. asoca extract-based chitosan microspheres conferring sustained released to enhance its medicinal use. Materials and Methods: A data mining online tool was used to check the interactions between the polymer used and formulation properties to analyze the relationships between them. The method uses a formulation of chitosan: polyethylene glycol (PEG) (2.1:0.9), drug (18.13%), sodium tripolyphosphate (6.55%), and crosslinking time (34.44 min) with a very good encapsulation efficiency and drug release. Results: The optimized formulation have showed an average particle size of 1157 nm, encapsulation efficiency of 73%, and drug release of 1052 mg GAE. In vitro release studies have shown a sustained release profile with maximum release till 24 h in pH 7.4 phosphate-buffered saline. The flowability of the optimized microparticles has shown a better Carr's index of 19.90 ± 0.21% and Hausner ratio of 1.24 ± 0.03. In vitro antioxidant activity of crude drug and microparticles has IC50 of 250.8 μg/mL and 188.2 μg/mL, respectively, showing an increase in the activity. Conclusion: Chitosan-based S. asoca microspheres with enhanced encapsulation efficiency, in vitro drug release as well as improved in vitro antioxidant activity could be attained by chitosan-PEG coated microparticles. Abbreviations used: PEG: Poly ethylene glycol; TPP: Sodium tripolyphosphate; GAE: Gallic acid equivalent; DSC: Differential scanning calorimetry.